In the spinning process, slivers are drawn and twisted into rovings by a roving frame, which rovings are then wound around roving bobbins (hereinafter referred to merely as bobbins) by a fly frame. The bobbins are sent to a ring spinning frame, whereby the rovings are unwound from the bobbins. In this case, previous rovings remain on the bobbins which are returned from the ring spinning frame to the roving frame, and it is necessary to remove them before fresh rovings are wound on the bobbins.
To automatically remove such rovings from the bobbins, U.S. Pat. No. 3,940,825 discloses a system which includes a first step to keep a moving endless belt in contact with the outer surface of the bobbins while the belt is rotated in a direction in which the waste rovings are unwound, and a second step to convey the bobbins while keeping contact with a moving flocked belt (having flocks planted thereon) so as to remove the remaining rovings from the bobbins.
Recently there is a practice to use a cloth commonly called a sticking cloth which has flocks planted on its surface, the sticking cloth being attached to a surface of each bobbin. This is effective to facilitate the automatic operation of a roving frame. The flocks are inclined in one direction so as to entwine the rovings with the flocks, thereby facilitating the winding of the rovings in the fly frame.
When the sticking cloth is used, the problem is that the waste rovings also remain on the sticking cloth on each bobbin. The prior art apparatus, such as that disclosed in the noted U.S. Patent, are not suitable for removing the rovings remaining on the sticking cloths.
A further problem is that the amounts of waste rovings on the bobbins differ from bobbin to bobbin. When the rovings are removed, the amounts of them must be taken into consideration, but the prior art apparatus has no special expedient for coping with such variations in amount. Especially when a large quantity of rovings remain on the bobbins, the prior art apparatus has difficulty in removing them completely.